Gas fumigation as currently practiced uses either ethylene oxide (epoxyethane, ETO), formaldehyde, vaporized peroxide or ozone. Each of these fumigants has disadvantages that limit their utility in fumigating large volumes, e.g. buildings or vehicles. Ethylene oxide is a flammable and explosive gas that is classified as both a mutagen and a carcinogen. The use of ethylene oxide as a fumigant requires extensive post detoxification and clean up procedures. Formaldehyde is potentially explosive and an occupational carcinogen. Moreover, it has poor penetrating ability. The use of formaldehyde as a fumigant requires extensive post detoxification and clean up procedures. Vaporized peroxide reacts generally with all organic compounds in the environment to be fumigated, thus having a high demand for fumigant. Vaporized peroxide is effective in fumigating spaces of volume less than 1200 ft3. Ozone reacts generally with all organic compounds in the environment to be fumigated, and has the shortest half-life of these fumigants, making ozone even less suitable than vaporized peroxide for the fumigation of large volumes.
Chlorine dioxide is recognized as an effective sterilant. However, no guidance is available regarding the use of chlorine dioxide for the fumigation of large volumes. Sodium hypochlorite is known to be useful and effective for scrubbing down surfaces. However, such procedures using sodium hypochlorite are labor intensive, affect appearance and integrity of materials scrubbed, and are not as suitable for large scale use as are the gas methods. Chlorine gas is also not suitable due to the health hazards, high corrosivity of the gas, and the production of chlorinated organic by-products.
Chlorine dioxide, which is a selective oxidant and a protein synthesis deactivator, has been reported to be efficacious against Bacillus subtilis (a gram positive, chemoorganotroph spore former similar to Bacillus anthracis) under controlled laboratory medical sterilizer conditions.